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exam [2011/07/19 14:00]
131.246.18.253 [Calculi]
exam [2011/08/02 15:29] (current)
188.107.127.174 [Core HOL]
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 :?: How are the elements //True// and //False// introduced in HOL? :?: How are the elements //True// and //False// introduced in HOL?
-  * Since there should always be an infinite set in **U** whose elements and power sets are also fully contained in **U**, there'​s a guarantee that there will be a set with two elements and that set is going to represent ​the values //True// and //False// ((Did I miss something?​))+  * Since there should always be a distinguished ​infinite set in **U** whose elements and subsets ​are also fully contained in **U**, there'​s a guarantee that there will be a set with two elements ​(say the subset {0,1} of the infinite set) and that one is going to be mapped further on to the values //True// and //False// ((Did I miss something?​))
  
 :?: Why must all functions be total in Isabelle/​HOL?​ :?: Why must all functions be total in Isabelle/​HOL?​
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   * A deductive system is sound if all provable formulas are valid. It is complete if all valid formulas are provable.   * A deductive system is sound if all provable formulas are valid. It is complete if all valid formulas are provable.
   * Validity is a semantic property ($A \models B$), while provability a syntactic one ($A \vdash B$). So, in other words we have:   * Validity is a semantic property ($A \models B$), while provability a syntactic one ($A \vdash B$). So, in other words we have:
-      * Soundness: $A \vdash B \rightarrow ​A \models B$ +      * Soundness: $A \vdash B \longrightarrow ​A \models B$ 
-      * Completeness:​ $A \models B \rightarrow ​A \vdash B$ +      * Completeness:​ $A \models B \longrightarrow ​A \vdash B$
  
 :?: What are the advantages/​disadvantages of the Hilbert ​ calculus compared to the Gentzen calculus. :?: What are the advantages/​disadvantages of the Hilbert ​ calculus compared to the Gentzen calculus.
exam.1311076846.txt.gz · Last modified: 2011/07/19 14:00 by 131.246.18.253